Steam boiler and water-heater



June 4, 1935. E. F. SPANNER STEAM BOILER AND WATER HEATER Filed June 11, 1934 2 Sheets-Sheet 1 ward rank spanner INVENTOfi 84g ATTY.

June 4, 1935. E. F. SPANNER 2,003,980

STEAM BOILER AND WATER HEATER Filed June 11, 1934 2 Sheets-Sheet 2 aya.

I TOR m WM k A.TT\1

.Edword rank Spanner Patented June 4, 1935 UNITED STATES 10 Claims;

This invention is concernedwith steam boilers and watereheaters of .the type in which a substantially vertical cylindrical or slightly conical firebox is fitted with substantially horizontal thimble tubes projecting inwards towards; the axis of. the firebox, the firebox with its internally projecting tubes being fitted in a watertight manner into a water-containing. boiler or .Waterheater shell, in such fashion that the application of heat within the firebox by the combustion of fuel or the influx of hot gases, results in heat being conveyed through the surfaces of the thimble tubes to the water. in the Water-containing shell,.so that steam is raised or Water heated as maybe desired,.necessary access and egress of the products of combustion or the hot gases to andfrom the firebox being provided, as maybe expedient, and in accordance with known practice. 1

In thimble tube boilers or water-heaters of such type, the practice hitherto has been to arrange for the thimble tubes inwardly projecting into the firebox space and in any one substantially horizontal peripheral row or layer, to be of uniform section and of the samesize but of difierent lengths, or slightly conical and of different size and the same length, the tube sizes and lengths being determined by various practical considerations, such as heating surface required, suitability for manufacture and so on. Where the inserted tubes are of uniform section and of the same size,.but of different lengths, there is, in practice, an unavoidable inefficiency of the combing action towards the periphery of any horizontal layer of tubes. Where-the tubes in each layer are slightly conical to form thimble tubes of the same length, there is, in practice, an unavoidable space left in the centre of any horizontal layer of tubes. 1

This'space, through successive rows of tubes, is sometimes fitted with a cylindrical wall, and usefully employed'as a channel for the admission of fuel or forthe admission or emission of the gases used for heating, orit is-sometimes occupied'by a solid or hollow balfie, or baffling cups or plates,

which serve no useful purpose other than that of area of the annular space-through which the hot gases flow overthe thimble tubes towards the outflow end relatively to that towards the inflow end tocause the rate of flow of these gases when cooled byandaf-ter passing over the thimbles to tendto be substantially the same as their rate of flow ,over the thimble tubes towards the inflow end-of said. annular space by varying the number of thimbles in the annular rows or by varying .the dimensionsof the thimbles in which latter case the thimbleswhich lie in each rowrin the gas space towards the outflow end of the generator may all or some of them be somewhat larger in diameter'than the thimbles which lie near the inflow end.

in each substantially horizontalperipheralrow or layer, of slightly conical thimble tubesof different lengths and sizes interspacedwith one another in'each layer, in such a way that practi- 1 cally the whole oi' the cross section ofthe firebox is usefully crossed by substantially horizontal thimble tubes.

The invention is carried intoeifect by providl0 :The present invention provides for the'fitting,

ing and. fitting, slightly conical thimble tubes of different lengths and diameters, so arranged that each set of. thimble tubes combs thewhole of a definite sector or part area of the cross section ofv the firebox. By fitting a completeset of such sectors oripart areas, the whole or-the greater part ofthe cross section of the firebox may be usefully combed by the thimble tubes. Where it is desired, for some reason, to retain some part of the'firebox cross section clear of thimble tubes,

theinvention provides that such clear space'may be left as required to suit the needs of the case, the remainder of the cross section, however, being sector-ed or sub-divided, and combed by sets of conical thimble-tubes of varying lengths and sizes as already described.

The invention. further, provides that, successive horizontal layers of thimble tubes may be rotationally displaced relatively to one another inwell: known manner, a particular advantage being, obtained in the present invention in that 40 Where it is desired to, leave some'part of the firebox cross section clear of thimble tubes, the invention provides that if desired a cylindrical or otherwall maybe'fitted to provide a channel for fuel-or gases to meet requirements; also that a thin wall or bafiie plate may be inserted among the thimble tubes, if desired, in 'order'to-assist in promoting any desired direction of flow.

' Although principally intended for'fireboxes of cylindrical shape, the invention can. be adapted to serve fireboxes of triangular, rectangular or square cross section such as might be convenient in certain cases.

Referring to the accompanying drawings:-

Figures 1 and 2 show respectively a vertical and horizontal section through a steam boiler or water-heater in accordance with this invention. In these drawings A is the water space, shown cross-hatched and filled to working height; B is the firebox space into which project the thimble tubes C, D and E, these thimbles being of different lengths and sizes as shown. The hot gases or products of combustion enter thefirebox B through the inlet G, and passout from the firebox through the uptake N. The cross section shown in Figure 2 is takenthrough ab.

Figure 4 shows a development of the circumferential plate of the firebox B, indicating one manner in which the successive peripheral layers of tubes may be rotationally displaced relative to one another and clearly showing that the gas 'may be given a spiral fiow or a zig-zag fiow simply by properly choosing the amount of the rotational displacement of successive rows of tubes.

Figures 3, 5 and 6 show sectional plans, taken between adjacentlayers of tubes, in steam boilers or water-heaters having two, three or four substantially vertical fireboxes of the cross-sectional shapes shown. It will be noted that, in these cases, the two, three or four fireboxes are so shaped in cross section that they can be placed relatively to one another in such a manner that the curved sides of fireboxes in which the thimble tubes are mounted face outwards towards the water space, so that the tubes are very easily inspected on their insides. The cross-hatching makes it clear that the water in the water space flows completely around all the fireboxes, these being quite independent of each other. Suitable stays are fitted to support the flat sides of the fireboxes, and to hold these in proper relation to the shell ofthe boiler or water-heater. The purpose of these arrangements is to provide that separate fireboxes in accordance with this invention may be available within a common external boiler or water-heater shell, these individual fireboxes being capable of taking, simultaneously, hot gases from different engine exhausts or the products of combustion from coal or oil fuel fired furnaces, without interfering with one another.

Figure 8 shows a vertical section through a steam boiler or water-heater such as is shown in section in Figure 3, in which the separate fireboxes B1 and B2 are respectively heated by coal or an oil burner, and by hot exhaust gases. It will be noted that the two fireboxes are quite distinct from one another, and that there is no communication between these two fire boxes inside the ,boiler or water-heater, although the discharges from the fireboxes go to a common uptake.

In Figure 7, one firebox B is shown communicating with two inlets, one for-exhaust gas G, and one for an oil burner O. This boiler or waterheater is capable of being operated either with exhaust gases, or with an oil burner. The two methods would not be operated simultaneously in practice.

In Figure 8, the arrangement shown permits of both forms of heating medium being employed at the same. time, since this can be done with no interference between the two fireboxes.

In Figures 7 and 8, A represents the water space. It is shown cross-hatched over the wholevolume to which water can gain access. B, B1 and B2, each represent a firebox in accordance with the invention. C, D and E, are thimble tubes. F denotes a corrugated furnace of known type or its equivalent. This is fitted between the firebox and the outer shell of the boiler or water-heater, and passes through the water space. K shows refractory material which may be fitted at the bottom of the furnace if desired.

R denotes an uptake, preferably corrugated, communicating from the top of the firebox to the upper shell of the boiler, where it leads into the uptake. S denotes supports shown of corrugated form to sustain the firebox.

In order to assist in extracting heat from the hot gases passing up through the firebox, in the case of fireboxes having fiat sides, such as are shown in Figures 3, 5 and 6, the invention provides that horizontal projections or fins or bafiles may be fitted to these vertical sides in order to prevent the gases from shooting straight up along the surfaces of those fiat sides. These are not shown in the drawings.

Figures 9 and 10 show an adaptation of this invention, in which, by the suitable positioning of a battle plate, the direction of fiow of the hot gases of products of combustion may be controlled within a firebox fitted with tubes in accordance with this invention. Figure 11 shows a section through a -b in Figures 9 and 10, and indicates that the area on the outlet side is smaller than the area on the inlet side of the bafile plate. In these drawings A is the water space, B is the fire box, W is the bafile plate, G is the inlet for the hot gases and N the outlet.

Figures 12 and 13 show an elevation and section respectively of a steam boiler or water-heater in accordance with the invention in which superheater steam piping V is fitted in conjunction with superheater baffle plates P. The other letters have the same significance as have similar letters in the other figures.

In all of these drawings, the arrangements shown are purely diagrammatic, and simply to 11- lustrate some of the various ways in which fireboxes in accordance with this invention may be conveniently arranged, and incorporated in steam boiler or water heater construction. These arrangements may be modified or amplified in any manner desirable to meet the needs of particular cases, and as may be necessary to avoid undue stresses and strains when the boilers are in action. Furnaces, thimble tubes, baifies, inlets, outlets or uptakes, fireboxes, means of access, feed water supplies, safety valves, steam blowers, superheaters etc., etc., may all be provided as required and in accordance with known practice. If preferred, the coal or oil burner furnace may be arranged below or alongside of the water space instead of being entirely surrounded by water as shown in Figures '7, 8 and 12. This is a matter to be determined according to requirements. Similarly if preferred, the inlet and outlet for the hot gases or products of combustion in Figures 9 and 10 may be arranged to pass through water jacketed furnaces somewhat as shown in Figure 7 and 8. 1

An alternative arrangement for the superheater steam piping may be provided in which this piping is arranged so that it may be withdrawn through the inlet for the hot gases, while provision may also be made for steam blower piping for cleaning the fire side of the thimble tubes. These are all matters of practical design.

I claim:-

1. In a steam boiler having a tube plate forming a passage for hot gases; a shell enclosing said tube plate to form a water space; and a plurality of horizontal rows of slightly conical thimble tubes in said tube plate each of said thimble tubes communicating with said water space and extending radially into said passage: the arrangement of the thimble tubes so that slightly conical thimble tubes of different lengths and different sizes are interspaced in each horizontal row.

2. In a steam boiler having a perforated wall forming a passage for hot gases; a shell enclosing said perforated Wall to form a water space; and a plurality of horizontal rows of slightly conical thimble tubes in said perforated wall, each of said thimble tubes communicating with said water space and extending radially into said passage; the arrangement of slightly conical thimble tubes of difierent lengths and difierent sizes interspaced in the horizontal rows to constitute efiective helical baffle surfaces for defining spiral paths to the hot gases.

3. A steam boiler having in combination a plurality of curved tube plates and radial walls to form sector shaped passages for hot gases, a circular shell enclosing said passages to form a water space surrounding said passages and a plurality of slightly conical thimble tubes arranged in each tube plate in horizontal rows of tubes of different lengths and different sizes interspaced in each row, each of said tubes communicating with said water space and extending radially into a passage.

4. A steam boiler having in combination a tubular tube plate; a partition arranged diametrically within said tube plate to form passages for hot gases; a shell enclosing said tube plate to form a water space; a plurality of horizontal rows of slightly conical thimble tubes of difierent lengths and different sizes interspaced in each horizontal row in said tube plate, said thimble tubes communicating with the water chamber and extending radially into a passage.

5. A steam boiler having in combination a tubular tube plate; partitions arranged radially within said tube plate to form passages for hot gases, a shell enclosing said tube plate to form a water space; a plurality of horizontal rows of slightly conical thimble tubes of different lengths and difierent sizes interspaced in each horizontal row in said tube plate, said thimble tubes communicating with the water chamber and extending radially into a passage.

6. A steam boiler having in combination a chamber having a perforated wall; an inlet to said chamber, an outlet from said chamber and a partition within said chamber to form a passage for hot gases, a shell forming a water space surrounding said chamber, a plurality of slightly conical thimble tubes arranged in said perforated wall in rows of tubes of different lengths and difierent sizes interspaced in each row, each of said tubes communicating with said water chamber and extending radially into said passage.

7. A steam boiler having in combination a cylindrical tube plate forming a combustion chamber, a shell enclosing said combustion chamber to form a water space and a plurality of slightly conical thimble tubes arranged in said tube plate in rows of tubes of different lengths and different sizes interspaced in each row, each of said tubes communicating with said water space and extending radially into said combustion chamber.

8. A steam boiler having in combination a combustion chamber with a cylindrical tube plate, a shell enclosing said combustion chamber to form a water space about said tube plate, a plurality of horizontal rows of radially arranged slightly conical thimble tubes in said tube plate and communicating with said water space, thimble tubes of difierent lengths and different sizes being interspaced in each row and displaced relatively to those in adjacent rows so that thimble tubes of the same length and the same size in adjacent rows cooperate together efiectively to constitute helical baffles defining spiral paths for hot gases.

9. A steam boiler having in combination a cylindrical tube plate forming a combustion chamber, a shell enclosing said combustion chamber to form a water space about said tube plate, a plurality of slightly conical radially arranged thimble tubes of different lengths and different sizes arranged in horizontal rows in said tube plate, the several horizontal rows being displaced relatively to one another to control the flow of hot gases and to set up a defined temperature slope along each tube from a maximum temperature at the part located remotely to the tube plate.

10. In a steam boiler having a tube plate forming a passage for hot gases; a shell enclosing said tube plate to form a water space; and a plurality of horizontal rows of slightly conical thimble tubes in said tube plate, each of said thimble tubes communicating with said water space and extending radially into said passage; the arrangement of the thimble tubes so that slightly conical thimble tubes of different lengths and different sizes are interspaced in each row, each row being displaced relatively to adjacent rows to locate similar tubes in adjacent rows in a plurality of unidirectional spiral paths.

EDWARD FRANK SPANNER. 

